Oil burner nozzle



Dee:- 26, 1939.. P. c. ROTH 2,184,47

on. BURNER' Nozzns l Patented Dec. 26, 1&3

OIL BURNER NOZZLE Paul C. Roth, New York, N. Y., assignor to Boiler Room Equipment, Inc., New York, N. Y., a

corporationot New York Application October 12, 1937, Serial No. 168,551

1o olaims.- (c1. 15s-77) This improvement relates to oil burners of theY type having a rotary oil cup which is rotated at relatively high speed, the oil being fed in at the rear end of the cup and discharged by rotation 5 of the cup at the open end in a whirling cone or sheet of spray. The rotaryoil cup is surrounded by an annular air nozzle connected with a primary air conduit supplying air at the required pressure, the nozzle havingair swirling `varies therein from which the primary air is discharged against the cone or sheet of spray discharged from the oil cup. This swirling primary air meeting the oil spray atomizes the oil and provides the initial air required for combustion, auxiliary air being .supplied from another conduit as required. The flame produced by the burner is substantially conical. l

There are two principal types of oil burners utilizing a rotary oilcup, one type of oil burner being provided with a motor directly connected to a fan for supplying the primary air to the y nozzle and to the oil cup for rotating the same. The other type of oil burner isprovided with an air turbine for rotating the oil cup and air at the desired pressure supplied from an outsidesouroe,

this air'by passing through a suitable conduit being adapted to rotate the turbine and the oil cup, the air thereafter passing through the Vannular nozzle supplying the primary air ofcombustion for the burner. y

Oil burners of both of these well known types operate with reasonably satisfactory results as to efllciency when operating at substantially full capacity and down to 50% of full capacity, but when operating below 50% of full capacity, the eficiency drops rapidly for the smaller flames as a result of the reduced velocity of discharge of the air from the air swirling nozzle.

The steam pressure in a boiler or the like constituting the load carried by an oil burner frequently changes as the load of the boiler changes and the oil burner is provided with linkage connections arranged to be controlled by steam-pressure or otherwise for regulating the operation of the oil burner according to the requirements of the boiler. For this purpose, a valve is provided for controlling the amount of oil supplied to the rotary oil cup. Adjustment of the oil valve is preferably accompaniedby simultaneous control of the air by means of a buttery valve controlling the supply of air at the inlet end of the conduit leading to the annular nozzle from which the swirling air is discharged.

Obviously, under these conditions when the supply of oil is reduced by adjusting the oil valve to reduce the volume of the oil burner dame, the air pressure is simultaneously reduced in the air conduit so that in these known prior devices the velocity of discharge from the nozzle is reduced to such an extent that the emciency of operation g is greatlyimpaired.

Accordingly the object of the improvement, therefore, is to provide a. new type of nozzle wherein regulation of the swirling air discharged therefrom is made directly at the discharge openlo.

ing of the nozzle so as to maintain a substantially constant discharge velocity for the primary air;

yand itis found that, by so doing, a relatively hign and substantially 'uniform emciency is maintained for a wide range of low ame operation 1&5x

which compares favorably with operation of the burner at or near full capacity. For this improved air nozzle control, it is pref erable to provide an annular valve adjustably mounted in the forward end of the air nozzle 20 Awhich valve preferably divides the primary air stream into two parts, the outer part of the primary air passing through swirling vanes between the outer periphery of the valve member and the inner periphery of the Vnozzle and the other part 25 of the primary air passing through the annular valve member between its inner periphery and the outer wall of the rotary oil cup. It will be observed Vthat adjustment of the annular valve member axially of the nozzle is adapted to con- 30 trol the discharge of primary air through ther outer lpart of the nozzle while maintaining substantially constant the discharge through the valve member, to thereby maintain a substantially constant velocity of discharge for the primary 35 air for all adjustments of the oil feed as explained later.

' In order to provide for the adjustment of the nozzle valve member and to control the primary air through the nozzle, the discharge end of the 40 nozzle is preferably provided with an inwardly turned end so as to provide the nozzle with a discharge opening of reduced size as compared with .the inner periphery of the main body of the nozzle. The discharge end of the nozzle is pro- 45 `vided with the usual air swirling vanes over which the annular valve member is adapted to slide when adjusted to reduce the area of the outer discharge opening.

In order that the entire supply of primary air 50 Vbeing discharged from the nozzle may not vbe cut off by closing the air nozzle valve as described, that part of the primary air discharging from thelnozzle between the valve member and the rotaryvoil cup is not cut o' by closing the valve 55 and this continuous flow primary air is sumcient in quantity to maintain the minimum flame with reasonable efficiency, for the velocity of air discharge is maintained at substantially the normal rate. To provide for swirling this continuous ilow primary air the innerl periphery of the valve is preferably provided with short inwardly projecting vanes for this purpose.

A further object of the improvement is to provide connecting linkage between the oil control valve and the annular primary air valve in the nozzle for the simultaneous regulation of both the oil supply to the rotary cup and the primary air discharge from the nozzle and this connecting linkage can include the usual connection to the butteriiy valve for controlling the supply of air at the inlet to the primary air conduit.

For the purpose of illustration, the improved primary air nozzle with the associated control is shown in the accompanying drawings in connection with an oil burnenofthe motor driven fan and oil cup type; and it will be understood that with a few slight mechanical changes and adjustments, the improvement can be adapted to the air turbine oil cup type of oil burner.

In the accompanying drawings, Fig. 1 shows a side elevation of a motor driven type of oil burner partly in section to show the improved nozzle and its operativeconnections; Fig. 2 is an enlarged broken away section of the rotary oil cup and the valved nozzle; Fig. 3 is a transverse section of the nozzle on the line 3-3 of Fig. 2 and Fig. 4 is an enlarged cross section on the line 4--4 of Fig. l.

Referring particularly to Fig. 1 of the drawings, it will be seen that the oil burner assembly shown comprises a motor (not shown) mounted in the compartment I upon a shaft 2, the latter preferably being supported in ball` bearings 3. The end of the shaft 2 is screw threaded at 4 to receive the inner end of the rotary oil cup 5 which is secured to the shaft so that the oil cup will be rotated at high speed by the motor. As indicated in the drawings, it will be seen that the shaft 2 is tubular or hollow and provided axially thereof with an oil conduit or pipe 6 for conducting oil to the rotary cup 5. rI'he end of the pipe 6 projects into the cup 5 and is provided with a terminal cap 1 having perforations 8 for discharge of the oil laterally onto the inner wall of the rotary oil cup near its point of attachment to the shaft.

It will be observed that the interior of the rotary oil cup is conical or slightly aring toward its open end, so that by centrifugal force, as a result of the high speedof rotation of the oil cup the oil spreads out on the interior of the cup towards its open end in a thin film, which, when it reaches-the open end, is thrown off in a sheet of ne spray which is atomized by swirling air from the nozzle, so that substantially complete combustion can take place.

On the shaft 2, just back of the threaded end 4 thereof a pump or fan 9 is mounted, preferably of centrifugal type, the radial channels I of which have inlet openings I I near the hub, which are adapted to cooperate with an annular inlet chamber I2 having an inlet opening at I3 which is provided with the usual butterfly valve I4 for controlling the air entering the annular chamber I2 on its way to the fan. It will be understood that under certain conditions of operation, the buttery valve I4 may be discarded and the discharge of primary air from the nozzle controlled entirely by the annular valve in the nozzle.

valve member.

The fan 9-I0 is mounted in an annular chamber I which is provided with a partition I6 which, in cooperation with the front cover plate I'I of the fan chamber, provides a radial air passage merging with an annular conduit I8, the outer ends I9 of the fan channels III being arranged to cooperate therewith to provide the primary air in the annular conduit 20, upon the end of which the annular rozzle 2| of this improvement is mounted.

The improved nozzle is more particularly shown in the enlarged views of Figs. 2 and 3 and oomprises, in the present instance, a ring portion 22, internally threaded at 23 to flt the threaded end of the vannular primary air conduit 2l). This threaded portion 22 may be attached to or formed as part of the cylindrical nozzle body portion 24, the forward or discharge end of which is preferably provided with an in-turned portion at 25 to form a sloping end wall, the opening 28 in which provides the discharge opening of the nozzle. In the cylindrical body portion 24 of the nozzle 2|, the usual air swirling varies 2l are mounted substantially as indicated in Figs. 2 and 3, the front ends of these vanes preferably extending to and joining with the front end wall 25.

As more particularly indicated in Fig. 2, the inner edges of the air swirling vanes 2l are substantially parallel with the cylindrical body wall 24 of the nozzle 2l and an annular valve member 28 is mounted within the nozzle for axial adjustment relative to its discharge end, the outer periphery of the valve member sliding substantially in contact with the inner edges of the air swirling Vanes 2l.

This annular nozzle valve member 28 is preferably streamlined substantially as indicated in the cross section of the valve in Fig. 2, thereby to facilitate the passage of air over and around the The forward end of the valve member 28 is arranged by axial adjustment to cooperate with the end wall 25 of the nozzle 2I to vary the area .of the discharge opening for the primary air passing through the swirling vanes 2l.

It is preferable to have the annular nozzle valve 28, when closed or partially closed, cut off only a portion of the required primary air to the oil spray discharged from the oil cup 5, that is, the portion which passes through the outer air swirling vanes 21. Accordingly, the inner periphery of the adjustable valve 28, in the present instance, is spaced a short distance from the outer wall of the oil cup 5, as indicated in Fig. 2, and the inner periphery of the valve member 28 is provided with a plurality of air swirling varies 28, thereby providing a nozzle discharge channel with swirling means for the constant ow primary air passing through the nozzle, but this constant ilow air is not cut off or varied to any great extent by adjustments of the valve member 28 except that the velocity is maintained.

In this manner, it will be seen that when the spray discharge from the rotary oil cup is reduced by adjusting the oil valve, as described later, the discharge of primary air from the noz- V'---zle 2l is correspondingly reduced at the point of discharge so as to maintain substantially a constant velocity of air discharge from the nozzle,

which is required for the complete atomization of within the nozzle 2 l, any suitable means, such as the ordinary pin and slot connection may be provided. As shown in Fig. 2, the studs or pins 30 are bent at right angles and the inner horizontal portions thereof are set in sockets 3| at diametrically opposite points in the valve member 28 and the radially extending ends 30 bent at right angles are adapted to pass through slots 32 substantially as shown in Figs. 2 and 3.

It will be understood that the nozzle valve member 28 may be moved axially of thenozzle 2| for adjusting the discharge opening in any suitable manner, and for this purpose, in the present instance, the valve member 28 is provided at its rear edge with ears 33, at'diametrically opposite points, which are connected by links 34 with the Y-shaped arms 35 of a bell crank lever 36 pivotally mounted in supporting lugs 31 projecting inward from the fan chamber wall l1 and annular conduit member I8, as will be seen more particularly in Figs. 1 and 4. It will be understood that the Y arms 35 are adapted to extend on each side of the rotary oil cup so that the connected links 34, at substantially opposite diametrical points, are about horizontal in connecting with the nozzle valve 28.

The other arm 38 (Fig. l) of the bell crank lever 36 extends rearward and is connected by a link 39 with an adjusting link 40, the lower end of which, as indicated in Fig. 1, is connected by means of a connector lug 4l with a pivoted control arm 42, the latter being pivoted at 43. The control arm 42 is also provided with a crank arm 44 connected by means of a link 45 with a crank arm 46 connected to the spindle of the butteriiy valve i4, so that the latter is operated by adjustment of the control arm 42.

In the form of oil burner shown in Fig. 1, the casing at 41- encloses an oil pump adapted to supply oil through an oil control valve 48 leading into the' oil pipe conduit 6, which, as previously explained, discharges oil through the openings 8 on to the rear inner wall of the rotary oil cup 5.

For thesimultaneous control of the oil supply to the burner and the primary air supply to the nozzle, the oil control valve 48 is provided with an upwardly extending crank arm 49 which is provided with a link connection 5U pivotally connected to a depending crank arm 5| formed as shown, as part of the fulcrum head of the control arm 42. By this arrangement, it will be seen that any adjustments of the control arm 42 are adapted to correspondingly adjust the oil control valveA 48, the butterfly valve i4 and the nozzle valve 28. It will be noted that the linkage crank arms and f links are'provided with means, such as a plurality of pivot pin holes, for synchronizing the motions of the valves.

As previously explained, it willbe understood that when the control arm 42 is adjusted for regulating the oil burning llame by operation of the oil valve 48, the simultaneous adjustment of the nozzle valve member 28 will be effected so as to maintain asubstantially constant velocity of discharge of the primary air from the nozzle, whereby atomization of the oil sprayed from the rotary oil cup 5 will remain substantially uniform with the result that complete combustion with uniformly high eiiiciency for low flame operation can be maintained which is comparable with that for full capacity operation.

It will be understood that adjustment of the control arm 42 may be effected in the usual manner from the steam pressure of the associated boiler or otherwise by means of chains 52 in conjunction with the weight 53; this control not bel ing shown as it forms no part of the present invention.

The oil burner assembly is usually provided 'with a furnace door or wall portion 54 which is ordinarily provided with a funnel-shaped member 55 spaced from and surrounding the primary air conduit 2U and nozzle 2|, substantially as shown in Fig. 1, the channel 55 being adaptedto supply auxiliary air for combustion; but since the present improvement is not concerned with the auxiliary air, further -description lis not necessary.

While one form ofA the improved primary air nozzle valve and its associated control linkage connections for the simultaneous operation thereof and the oil control valve has been shown and described in connection with the motor driven oil cup type of oil burner, it will be understood that various modiiications in theI nozzle valve construction and in the arrangement for synchronizing operation of the various valves, may be made,

' particularly in adapting the improvement to other types of ,oil burners, without departing from the spirit and scope of the invention.

I claim:

1. In an oil burner the combination with a ro` tary oil cup of a primary air nozzle surrounding said oil cup and provided at its discharge end with an inturned annular wall having a valve seat, an annular valve member mounted for axial movement within said nozzle for cooperation with said end wall valve seat, to vary or cut off the discharge of primary air between said valve seat and the valve member, the inner periphery of said valve member being uniformly spaced from said oil cup to provide therebetween a substantially constant ilow discharge channel for the primary air, the flow through said channel being substantially constant in any position of the valve member, and means -for moving said valve member for varying the discharge of primary air.

2. In an oil burner the combination with a rotary oil cup of an oil valve and pipe connections for supplying oil to the oil'cup, a primary air nozzle surrounding the oil cup, an .annularv valve member movable axially within said nozzlev for .controlling the discharge of primary air at the nozzle, said valve member being spaced from the oil cup to provide therebetween an annular substantially constant ow discharge `passage for the primary air, movement of said valve member being adapted to vary thev discharge of primary air from the nozzle but Without varying said substantiallyV constant ilow discharge through the valve member, and control means including linkage connections between said oil valve and said nozzle valve member for simultaneous operation thereof to vary in unison the discharge of primary air at the nozzle and the supply of oil to the oil cup.

3. In anoil burner the combination as in claim 2 wherein said primary air nozzle has its discharge end turned inward for cooperation with the movable valve member as a valve seat, movement of the valve member being adapted to cut off or vary the discharge of primary air over the outside of the valve member without varying the substantially constant ow discharge through the interior of the nozzle valve member.

4. In an oil burner the combination as in claim 2 whereinv said annular valve member is streamlined in its axial cross section to facilitate the passage of the continuous flow primary air therethrough. f

5. In an loil burner the combination with a rotary oil cup of a primary air nozzle surrounding said oil cup and provided at its discharge end with an inturned annular wall having a valve seat, an annular valve member mounted for axial movement within said nozzle for cooperation with said end wall valve 'seat to vary or cut oil' the discharge of primary air between said valve seat and the valve member,` the inner periphery of said valve member being uniformly spaced from said oil cup to provide therebetween a substantially constant ilow discharge channel for the primary air, the ow through said channel being substantially constant in any position o! the valve member, means for moving said valve member for varying the discharge of primary air, and a plurality of swirling vanes extending along the inner periphery of the nozzles from said end wall but clear of said valve seat, the inner edges of said vanes being equally spaced from and parallel with the axis of the nozzle and cooperating with said valve member to guide and support the same in its axial movement. A

6. In an oil burner the combination with a rotary oil cup of a primary air nozzle surrounding said oil cup and provided at its discharge end with an inturned ,annular wall having a valve seat, an annular valve member mounted for axial movement within said nozzle for cooperation with said end wall valve seat to vary or cut' ofi the discharge of primary air between said valve seat and the valve member,` the inner periphery oi said'valve member being uniformly spaced from said oil cup to provide therebetween a substantially constant ilow discharge channel for the primary air, the surface of the interior of lSaid valve member forming one wall of the substantially constant iiow primary discharge channel being streamlined in the direction of now, the ow through said channel being substantially constant in any position ot the valve member, and means for moving said valve member for varying the discharge of primary air.

7. In an oil burner the combination with a rotary oil cup of an oil valve and pipe connec- -tions for supplying oil to the oil cup, a primary air nozzle surrounding the oil cup, an annular valve member movable axially within said nozzle for controlling the discharge of primary air at the nozzle. said valve member being spaced from the oil cup to provide therebetween an annular substantially constant flow discharge passage for, the primary air, movement of said valve member being adapted to vary the discharge of primary air from the, nozzle but without varying said substantially constant flow discharge through the valve member, a rotary fan air pump for supplying primary air to said nozzle, a buttery valve at the inlet of said pump, control means including linkage connections between said oil valve and said nozzle valve member and linkage connections to said buttery valve for simultaneously varying thesupply of air to said pump, the discharge of primary air at the nozzle and the supply of oil to the oil cup.

8. In an oil burner the combination with a rotary oil cup of an oil valve and pipe connections for supplying oil to the oil cup, a primary air nozzle surrounding the oil cup, an annular ,said

valve member streamlined in axial cross' section and movable axially within said nozzle for controlling the discharge of primary air at the nozzle, `said valve member being spaced from the oil cup to provide therebetween an annular substantially constant ow discharge passage for the primary air, angularly disposed vanes on the inner periphery of said valve member for swirling the primary air, movement of said valve member being adapted to vary the discharge of primary air from the nozzle but without varying said substantially constant flow discharge through the valve member, and control means including linkage connections between said oil valve and said nozzle valve member for simultaneous operation thereof to vary in unison the discharge of primary'air at the nozzle and the supply of oil to the oil cup.

9. In an oil burner the combination with a rotary oil cup of an oil valve and pipe connections for supplying oil to the oil cup, a primary air nozzle surrounding the oil cup, an inturned annular end wall for said nozzle, angularly disposed vanes extending from said end wall along the inner periphery of the nozzle and cooperable with said end wall to direct the discharge of primary air from the nozzle, an annular valve member movable axially within said nozzle for controlling the discharge of primary air at the nozzle, said valve member being spaced from the oil cup to provide therebetween an annular substantially constant ow discharge passage for the primary air, movement of said valve member being adapted to vary the discharge of primary air from the nozzle but without varying substantially constant now discharge through the valve member, and control means including linkage connections between said oil valve and said nozzle valve member for simultaneous operation thereof to vary in unison the discharge of primary air at the nozzle and the supply of oil to the oil cup.

10. In an oil burner the combination with a rotary oil cup of an oil valve and pipe connections for supplying oil to the oil cup, a. primary air nozzle surrounding the oil cup, said nozzle having an annular portion which is screw vthreaded to the body of -the nozzle. an annular valve member mounted to move axially within said annular portion of the said nozzle, for controlling the discharge of primary air at the nozzle, the arrangement being such that said annular portion and thesaid cooperating valve member are removable 'as a unit, said valve member being spaced from the oil cup to provide therebetween an annular substantially constant flow discharge passage for the primary air, movement of said valve member being adapted to vary the discharge of primary air from the nozzle but without varying said substantially constant flow discharge through the valve member, and control means including linkage connections between said oil valve and said nozzle valve member for simultaneous operation thereof to vary in unison the discharge of primary air at the nozzle and the supply of oil to the oil cup.

PAUL c. Ro'rn. 

